


Chaos Theory (Walls)

by OoOMagnoliaOoO



Series: Omega verse [2]
Category: Shingeki no Kyojin | Attack on Titan
Genre: Alpha Erwin Smith, Alpha Mikasa Ackerman, Alpha Mike Zacharias, Alpha Reiner Braun, Alpha/Beta/Omega Dynamics, Alternate Universe - Canon Divergence, Armin is a manipulative little shit, Beta Bertolt Hoover, Beta Connie Springer, Beta Sasha Blouse, Bottom Armin Arlert, Canon Era, I Will Go Down With This Ship, Knotting, M/M, Mating Cycles/In Heat, Omega Armin Arlert, This Is Why We Can't Have Nice Things, Top Erwin Smith
Language: English
Status: Completed
Published: 2017-04-19
Updated: 2017-04-19
Packaged: 2018-10-21 01:28:38
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings, No Archive Warnings Apply
Chapters: 1
Words: 5,353
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10674879
Author URL: https://archiveofourown.org/users/OoOMagnoliaOoO/pseuds/OoOMagnoliaOoO
Summary: A butterfly flaps its wings… and it starts to rain.It all started with a confession. Because if Armin hadn’t told Eren his most well-guarded secret, none of this would have happened.In which a small change in one state of a deterministic nonlinear system can result in large differences in a later state.[Takes place parallel to “Levi doesn’t do romance… or Eren?”]





	Chaos Theory (Walls)

It hadn’t been this quiet in the shared sleeping quarters for a long time. Usually by now, Berthold - status: Beta - would have toppled over in his sleep; falling onto the hard, wooden floors. That would immediately be followed by his friend Reiner - an alpha with the musculature of an ox - getting his beta’s sorry ass back into bed. That in turn would lead to Sasha - also beta - to mumble in her sleep about unicorn, fairies and leprechauns, often something about wondering about the texture and taste of the meat. Soon after that, Connie - another beta, barely even taller than Historia; one of the two omegas of the 104th trainee squad - would get out of bed, stuff whatever he’d managed to sneak out of the mess hall into Sasha’s drooling mouth to get her to shut up; and soon head back to sleep. 

Connie’s tiptoeing would awaken Jean - alpha -, who would furiously yell out (or neigh as Eren would like to tease) that he desperately needed his sleep. Which immediately rose Eren - the alpha titan-shifter with the most wondrous eyes the Gods had ever created - which in turn  _ always  _ lead to an argument between the two. It would end when Mikasa - Eren’s alpha sister - conked the both of them over the head; finishing off the nightly routine. 

None of that could be heard tonight however, all of them completely knocked out from a strenuous training routine during the day. Captain Levi - alpha; although Armin had his doubts - had forced them all to first clean the toilets, followed hastily by the shower stalls and drains; ending only with a ten kilometer run that left even the most hardened soldiers slumping down in exhaustion. 

Most had been too tired to eat, forgoing dinner in favor of sleep. Reiner, who always seemed invigorated and graced with a limitless supply of energy, had been the first one to fall into his bunk; screws and wood protesting under the sheer force of his downfall. 

Others followed, unable to keep sleep at bay… 

All except for Armin. 

Armin Arlert - omega - lay awake through the early hours of morning, unable to fall into a near comatose state. No matter how many times he fluffed the pillows, spun around, tried making a nest out of the items in his bunk - he just couldn’t fall asleep. 

It was the fear, of the unknown, and the feeling of a new sensation. Every bone in his body felt loose and unconnected to the tissue, shifting uncomfortably. His heart was beating hard in his chest, shirt reverberating with each thump. 

The blond omega’s tired eyes felt heavy, but refused to shut. There was something wrong - and he was unable to put a finger on it… he was just…  _ off,  _ somehow. 

Sighing for the umpteenth time, and deciding that he wasn’t going to get some shut-eye anytime soon; he climbed down the ladder of the top bunk, throwing a quick glance at the sleeping stature beneath him. 

Eren was always a weird sleeper, to say the least. Some nights, he sprawled out like butter on bread. And others, he lay completely still and motionless for hours; not even making a single sound. 

Tonight was one of those nights. 

So against his better judgement - seeing as alphas were incredibly territorial - he climbed underneath Eren’s covers, snuggling up close. The brunet stirred slightly, eyes slowly beginning to part. 

“Armin?” His voice was deep with sleep, sort of rough and rugged. Had Armin been interested in the male alpha, there would have been nothing stopping the shorter man from jumping his bones. Alas, the blond had no such interest in the man beside him, other than using him as a heater that was. 

“Couldn’t sleep…” He muttered out in reply, letting his head rest on his best friend’s collar bone. 

“Why?” 

“Too many thoughts. It’s just too quiet. Bert hasn’t even fallen out of his bed yet.” Eren chuckled deeply underneath him, Armin’s head moving with every move the alpha made.

“That explains why Jean hasn’t woken up…” They were all like a well oiled machine, working in perfect synergy. It was a perfect example of the chaos theory. 

_ A butterfly flaps its wings… and it starts to rain.  _

Because if Berthold doesn’t fall out of his bed, Reiner won’t get up to help his friend back into his bunk. If Reiner doesn’t get up, Sasha won’t mumble. Then Connie wouldn’t have to get up to feed her, and wake Jean. Jean wouldn’t pick a fight with Eren, and if that happened; Mikasa wouldn’t intervene to stop it, putting an end to the nightly routine between the comrades. 

Armin nodded against the brunet’s collar bone. “Yeah… Jean won’t get up unless Connie feeds Sasha… Though, Connie wouldn’t have anything to feed her with anyway.” 

“True. We all skipped dinner. Even Sasha… which is incredibly strange.” 

The blond omega giggled. “You think? I’ve  _ never  _ seen Sash ignore dinner for sleep. I guess it’s been one of those days.”  _ One of those days, indeed.  _

There had been - on top of the brutal training - the annual physical that every soldier within all three factions had to attend. It didn’t matter if you were Garrison, Military police (*Cough*  _ replace with douchebags _ ) or Survey Corps ( _ A.k.a the only decent people left).  _ The yearly physical wasn’t overly intrusive, seeing as it only concluded a  _ soldier's  _ physical health and not that of your biological faction.

No, those took place after every heat or rut. Which was basically three or so months apart, and only ascertained whether or not you were fit for duty or needed to wait for another couple of days. 

Alphas had it easy; Armin thought begrudgingly. Their ruts lasted as long as an omegas heat, but were often less strenuous. They weren’t constantly worn out, exhausted and didn’t have legs that felt like wet clay. 

Sure, there were exceptions. Unmated alphas were forced to ride out their ruts without an omega - or in some cases betas, depending on your preference - which left them incredibly drained. He remembered Eren’s last rut, lasting well over a week, where the Squad Leader - Hange, a bonkers beta - had been forced to chain the brunet alpha to a pole for the duration of the time. 

Eren had left the room looking worse than after one of Captain Levi’s training  _ slash  _ cleaning drills, heading straight for the bunks. Jean wasn’t better, but instead of being calm and exhausted in his behavior after the week; he got violent, often picking fights left and right. 

_ Stupid alphas and their domineering hormones. And omegas for their submissive ones.  _

While Armin was omega, he’d never once experienced a heat. His body just wasn’t ready to take on a mate… at least not physically. 

But he knew exactly who to call on when the time came. 

Flashes of a blond alpha, strong and tall as a steeple (twice as muscled), came to mind. His azure blue orbs that Armin couldn’t gaze into for too long, afraid he might get caught in the abyss. Graced with incredible beauty, he stood proud. Lean, with biceps and abs that would put the God’s to shame. 

His lips were full, but not overly thick, with a strong protruding jaw line. The alpha had a predominant nose, completed with an aristocratic curvature, and big, caterpillar like eyebrows that Armin found somewhat charming. 

He was the picture of sophisticated grace, as well as the image of a perfect alpha. Strong, tall, handsome and caring. 

While many would deny it, Erwin Smith - alpha extraordinaire - cared deeply for everyone under his charge; whether he liked to admit it or not. As did Levi, but that man was the opposite of what an alpha should look and be like. 

If anything, he behaved more like a beta… or-

“Armin?” The blond’s head whipped up. “Are you still awake?” 

“Yeah… Just thinking again.” 

“About what?” The alpha asked. 

“About… someone…” Eren smirked, teasingly poking his friend in his sides. 

“ _ Someone special? _ ” He almost sang mockingly. The blond omega giggled again, contemplating telling the man. He had after all been Armin’s only friend growing up - apart from Mikasa. 

“I just… yes… it’s someone special.” 

Eren’s brow shot up, but he never lost the smirk. He shrugged the smaller male off him, leaning onto his elbow for support. “It wouldn’t happen to be little ole me by any chance?” Armin shook his head. 

“No, Eren, for the millionth time; you’re not my mate.” There was an unmistakable pout, but not for the reasons one might think. Eren wasn’t disappointed that Armin wasn’t his mate, rather he was upset at the fact that no matter how much he probed; the blond wouldn’t share the information. 

He’d slipped up once, admitting to the alpha that his mate had beautiful blue eyes; which described a lot of the Survey Corps members. After that, there was no keeping Eren’s guesses at bay, but at least over the past few months - the questions had dwindled. 

“Alright… you’ll tell me when you’re ready, I suppose.” He muttered, still pouting. Sighing in defeat, Armin buried his face in his hands. 

“If I tell you, will you stop nagging me?” 

The alpha smiled widely. “Yes. Just tell me who it is, Ar.” 

The omega groaned, embarrassment reaching through every part of his body; down to his fingertips. “Commander Smith.” 

Eren stiffened beside him, unsure of how to react. “Erwin? Your mate is fucking Erwin Smith? Armin… why haven’t you told him?” The blond hushed his friend, trying to keep him from rousing every person in the room. There was no need for this to reach the Commander’s ears through gossip. 

“I’ll tell him when I’m ready.” 

“Armin… he’s your mate.” The omega shoved his friend in annoyance. 

“You’re an alpha, Eren… you wouldn’t understand.”  

“No, I do understand, Armin. I understand that you’re scared, and while I don’t exactly approve… I still thinks that he deserves to at least  _ know  _ that you’re mates. I’d want to if this were my mate.” Never in his nineteen years had Armin heard an alpha say such things. 

It would usually go differently. Something along the lines of:  _ “He’s your mate, you’re basically his birthright” or “You can’t keep this from your alpha. You belong to him.” _ . Belonging to someone - bah, fuck that. 

Armin wasn’t a nice piece of furniture to conveniently store a knot inside, just because he was born to lie back and take it. No, he wanted more than just  _ belonging  _ to someone. Ownership of omegas wasn’t uncommon in the undergrounds, where alphas forcefully tore their counterparts from their home to rape, possess and knot - but above ground, it was illegal. 

That didn’t stop alphas from at least, in some regard (whether they did it purposely or not), trying to. There were after all such biological things as mating, knotting and bonding for a reason. But when Armin finally decided to tell his alpha of their connection, it would be because he knew that Erwin would never abuse the privilege of being just that - an alpha. 

Or God forbid, lay a hand on his omega. Armin knew that the Commander was kind in many ways, but once they rutted - there was no filter between their knots and brains. Almost as if they became one. 

“Ever heard the expression ‘stop thinking with your little head’?” Eren snorted. 

“No… what does it mean?” 

“It means stop thinking with your dick.” 

They both fell into a fit of giggles, as they exhausted each other into a dreamless sleep. 

__ Finally…  
  


* * *

 

_ What the everloving Hell is Eren up to?  _

Armin watched from far up high, executing his move perfectly. But Eren decided to do a quick turn; almost bumping into Jean. When they all landed, the Captain - who previously seemed wrapped up deep in thought - stomped over to the brunet alpha. 

“Yeager! For fucks sake, were you dropped on your head as a child?” Eren started stuttering, unable to answer for a moment. 

“S-sorry, sir… I didn’t mean to… it just… happened?”  _ Oh Lord save us all from Eren Yeager’s stupidity…  _

“Are you asking or making a statement? You know what, it doesn’t matter. You’re either sure or you’re not. I assume that you at least have some brain capacity to realize that you don’t do a one-eighty during the middle stages of your spin?” The worst part about Captain’s words was that they were true. Yes, Eren should know this; and yet… 

He’d been distracted for days now, ever since he’d shared his secret with the alpha. 

“Y-yes, Captain… or no… wait, I- ehm… yes?” Armin face-palmed, pretty sure that he had just slapped his brain into a frenzy. The harsh touch to his own face must have knocked something loose, because in the next second - he swore that Levi muttered ‘ _ stupid mate’  _ under his breath. 

“Everyone else may leave… Yeager, you’re staying behind.” Armin was prepared to leave, but came to a halt once he realized that Mikasa was still trying to stare their Captain into submission. He obviously wasn’t taking the bait, and the blond omega hooked his arm in hers, leading the raven-haired alpha back towards the Mess. 

 

* * *

 

“I’m worried about Eren.” Forty minutes had passed since the brunet alpha had been asked to stay behind, and Armin couldn’t help but to wonder just how many bruises the guy would have when he returned. He’d never seen Captain Levi lay a hand on him - apart from during the trial - but then again; he’d never been this angry before. And they would heal before anyone else saw them, so he had total deniability

“He brought it on himself.” Jean replied in a smug tone. It was no secret that the two alphas rarely got along, and often added atop a huge mountain of rivalry, but he could have at least acknowledged that Eren might be in trouble with the Captain. 

Armin shook his head. “Not really… it’s sort of my fault. I told him…” He paused. “ _ Something…  _ and he’s been distracted ever since. I don’t think he’s taking it so well.” Jean shrugged, raining down a mountain of mushroom stew onto his plate. Armin did the same, albeit a smaller portion, and headed towards the table. 

“I dunno…” The two-toned alpha started, flinging one leg over the bench. “I mean sure; it’s a pretty huge deal to be the Commander’s mate, but-” Armin cut him off by slapping his hands over Jean’s mouth. 

“H-how did you find out?” Connie snorted beside him, grabbing his cup. 

“You do know that you two whisper pretty loudly… and we weren’t really asleep.” Connie was a beta, so he would have no idea why Armin chose to keep it a secret… but Jean was an alpha. The moment the blond omega removed his hands, the two-toned neighing motherfucker just spewed word-vomit. 

“Dude, you’ve gotta tell him. He’s your mate… he-” Armin shook his head firmly. 

“No, I don’t have to. There are no laws that forces me to if I don’t wanna. And as your friend, and as a person that has an extensive knowledge of your most embarrassing stories, I don’t want you to say anything either.” Jean looked unimpressed, stuffing his face with stew. “You don’t think I’m being serious?” The alpha cocked an eyebrow as to tell the omega that; no, he didn’t think he was. Armin smirked deviously. “Alright… I’m game. Fourth day of training when you-”

The sweet sound of the two-toned alpha choking on his food was like music to his ears. The omega leaned back, grabbing his own cup and taking a swig. 

“Kirschtein?” A booming voice behind Armin almost made the drink go down the wrong pipe. He was startled to say the least, considering that he hadn’t even heard someone approach. “Are you alright?” 

Jean nodded, tears prickling the sides of his grey-ish eyes. “‘M fine…” He continued to cough, trying to rid his airway of the obstruction. Armin blushed furiously at the close proximity of his mate. 

Erwin placed a hand on the blond omega’s shoulder, and he jumped in surprise. The Commander quickly withdrew, afraid that he might have done something wrong. 

“Arlert?” Armin nodded at the sound of his surname. “I need you to come with me.” 

_ Oh no… he knows… he must have heard the entire conversation…  _

“What for, sir?” He asked. 

“There’s someone out front who wishes to speak to you. Said his name was Hannes, from the Garrison.” Armin was out of his seat faster than tavern whore smelling money. Erwin gracefully followed close behind and the omega quickened his step to gain some space. 

“Arlert… Arlert!” Armin didn’t stop to listen. “Armin, stop.” He halted, rooted to the ground. “The other entryway.” The omega cursed himself for not asking just  _ which  _ gate Hannes was at before rushing off like a child. 

“Of course, sir. Sorry.” He spun around, heading for the east gate, when Erwin stopped him. 

“Is something amiss?” Armin shook his head. 

“No, sir. Hannes is an old family friend, and I’d rather not keep him waiting.” The Commander alpha shook his head in reply, blocking the young omega’s path. 

“No really, what’s wrong?” 

Armin somehow managed to snake his way through the hallway, towards the east gate, avoiding Erwin Smith at all costs. 

 

* * *

 

His fuzzy mind started coming to, finally grasping reality again; although somewhat hazily. A dull throbbing harassed his aching back, an unbearable warmth grabbing ahold of him. Armin’s legs shook, and his skin itched horribly. 

_ Great…  _

Armin hated being sick. 

The fever this time was annoying as hell, making his most logical thoughts fly straight out the window. His sleeping attire needed to come off; and fast. So he did the most sensible thing, stripping down to his underwear and contemplated staying in bed for the rest of the day. 

But today was Thursday, which meant that Captain Levi had planned yet another maneuver training session that he simply couldn’t miss. He got out of bed, pulling on his freshly washed uniform; careful not to trip on his own unreliable feet. 

They felt like two cinder blocks, being pushed around by his weak legs. Lifting one off the ground proved disastrous as he fell, face first, into the wall. Armin clutched his aching nose, luckily not spotting blood, and steadied himself with the help of the wash basin; aiming to stay upright this time. 

The blond omega grabbed a hair-tie from Sasha’s stash (Right underneath the massive loaf of bread that needed to be eaten soon, lest it go bad) and gathered up his orion locks. It wasn’t bothersome yet, but he couldn’t concentrate on reaching the mess hall for breakfast without it out of his face; and eyes. 

Had he just stayed in his room, none of what came to follow would have happened. If Armin had taken a left, instead of a right, he would have ended up in the stables. Two minutes later; he would realize that this wasn’t the flu, and sat down in one of the stalls. 

Shortly after that, an unmated alpha would claim him, tricking him into a life of submission; until he, at age twenty, committed suicide - never having been able to bond with his one true mate. 

_ A butterfly flaps its wings… and it starts to rain…  _

The perfect chaos, for an imperfect situation. 

The omega stumbled through the corridors, reaching for walls just to hold on to. But everybody knew that walls could not hold you - quite literally as well as figuratively. Not even the massive walls erected around the cities could keep the Survey Corps from flying atop their noble steeds; reaching the skies with their gear. 

And the walls surrounding the distressed omega could no longer hold him up. He toppled onto the ground, clutching his chest. Somewhere down the corridor, an alpha approached; and Armin could smell his intent. 

Instead of staying down, he got up - fast - and made his way into the mess. Standing in the doorway, he caught everybody’s attention - pupils going wide. He was suddenly confused. They’d smelt him coming, although… why? 

This cold… 

_ Oh no…  _

This wasn’t the flu… 

Captain Levi met his gaze, and in that moment Armin knew… he wasn’t alone. The Captain wasn’t an alpha wanting to ravenously devour the small blond. 

He was an omega, seeking out his gaze to help. 

From the other side, rising from his seat, was his mate - making his way over to the heating omega. 

“C-captain?” He stuttered out. “Can you come here, please?” The raven omega did as told, sauntering over casually to where they were standing. He stood between Erwin and Armin, creating yet another metaphorical wall. 

From over Levi’s shoulder, the Commander leaned in to smell his mate. 

“Arlert, step back a few paces.” The blond omega did as instructed, stepping back cautiously. Erwin tried to follow, but was restricted by Levi’s apparent refusal to move. “Good. Now, Arlert, I’m going to need you to very carefully walk away without turning your back to him. Do you understand-”

Armin cut him off, standing his ground. 

_ It’s now or never.  _

“No… I’m not gonna run and hide from this any longer. I just want you to tell me that I’m making the right choice by staying.” He knew that it was foolish to ask the Captain of all people, considering that him and Erwin had been friends for years… 

But… 

It came from a place of uncertainty of  _ their  _ standing, rather than his own. The raven omega had been around the towering blond for a long time, and for them to at least mate once was a possibility. He wouldn’t want to impose, should Erwin choose Levi over him. 

If Levi were to protest, say something to throw dirt on the large alpha, Armin would know that it came from a possessive side on the raven-haired omega’s part and not to actually put him in a bad light. 

“No, I can’t do that.” Levi paused. “I can’t tell you whether to mate or not… it’s just something that you’re going to have to choose on your own.” The orion-haired omega sighed in relief, knowing now that there was nothing going on between the two. 

The rush of air through his lungs left his head feeling empty, which was unusual; considering that he was one of the most collected people out there. 

“I think I should move…” Erwin’s expression changed, going from lust to fear. Then another expression took over as Historia and Eren charged in; trying to help him remain on his feet. His mate’s growls send shivers down his spine. It was directed at his childhood friend, and Eren’s step faltered. 

“Commander…” He started. “Alpha to alpha… I’m not trying to steal your omega. But he doesn’t want to be here right now… Historia and I are going to help him back to his quarters.”

Levi stepped in, trying to defuse the situation. “No, Eren. Let Historia help, but you stay away from him. You need to back away, right now.” The brunet alpha did as he was told, taking a few cautious steps backwards. 

“A-alright… Commander-” Erwin still barred his teeth, making Armin’s hole wet further. By the walls, he wasn’t going to make it to his quarters before he needed to get stuffed with his mate’s knot. “-I’m going to back away from Armin now… very slowly. I’m not a threat to your omega,  _ alpha _ .”

Eren stood back, against the wall of the Mess, eyes lowered in submittance. But Erwin wasn’t backing down, and Armin had a good idea of why. 

_ Because of me… because Eren gripped my arm. Because Eren tried to help me. Because Eren’s another alpha. Because… _

They all had their demons, some more bolder than others, and it just wasn’t right that Erwin’s came creeping out at this moment. He - lacking a better word - was a possessive alpha. 

_ “He’s your mate, you’re basically his birthright” “You can’t keep this from your alpha. You belong to him.” _ . 

And Armin’s mind was back on that. Because hating was so much easier than letting go. Then again, he should be thankful that his alpha was like this. The blond omega knew how to deal with those. 

_ With threats…  _

“ _ Alpha. _ ” he called out experimentally, watching as Erwin’s walls crumbled. “Don’t hurt him. He’s my best… my- argh-” He almost doubled over with the new wave of heat hitting him. But he stood up, earning himself a proud look from Levi. “Eren’s my best friend.” The omega spoke confidently. “If you… if you lay a hand on him, you lose me;  _ forever _ .” 

It pained the alpha to back down, but his omega had laid down the rules… and Erwin wasn’t about to break them anytime soon. 

But biology was sometimes stronger than the rational thought. 

When Eren sighed, sagging in relief, and moving to step away from the wall; the Commander had seen it as a threat, launching towards the smaller alpha. 

There was suddenly a sweet smell filling the air, almost knocking Armin off his already unsteady feet. He held onto Historia for dear life, praying that she wouldn’t drop him. Before him, Levi stood - cravat removed - pheromones dancing in the wind. 

“Don’t!” He suddenly called out. “Don’t you dare hurt him, Erwin. If you hurt him, you hurt your mate…” His hand was raised, pointing at the heating omega. “A-and me. If you hurt  _ my mate _ , Eyebrows… I will hurt yours.” 

_ If you hurt my mate, I will hurt yours.  _

It suddenly clicked, everything falling into place. The real reason why Levi was so lenient with Eren wasn’t because he was trying to give the young alpha a break from an already stressful life. Rather, he was doing it because they were destined for each other; and Levi couldn’t stand the thought of his alpha being hurt in any way. 

Squad Leader Mike started crooning, aiming to soothe not Armin - who was the one who really needed it in this moment - but Levi. He guessed as much, judging by the looks they gave each other on occasion. Somehow, it bothered the blond to know that the Captain had chosen the Squad leader over his own mate. 

A sharp blade was put against his scent gland, the cold metal feeling both horrifying and calming at the same time. It offered some chill to his unbearable warmth. 

When his mate spoke again, his voice was rough and hoarse. “Don’t - you - dare -  _ Levi. _ ” 

“I  _ do  _ dare, Erwin.” Levi spat. “I will cut his gland, rendering him unable to bond with you. You will step away from  _ my alpha  _ or I will kill any chance you have of completing a bond with  _ your omega _ . Am I making myself clear, Eyebrows?” The threat had been effective, as Erwin immediately started walking backwards. 

“Alright… I’ll back off.” His gaze met Erwin’s, who took a few careful steps in his direction. “ _ Omega… _ ” Armin shuddered at his mate’s calling. “Please don’t fear me.” The blond omega shook his head, letting go of his friend. 

“I don’t fear you,  _ alpha _ .” He called out, stretching out his palm for Erwin to take in his own. “Take me to your quarters.” The alpha didn’t waste so much as a second, sweeping Armin off his feet and into his arms. 

He was carried off, towards his mate’s room. 

 

* * *

 

He was surprisingly gentle, placing his omega into the silk sheets, soft blankets and fluffy pillows. Alphas generally had no problems with itchy material, their skin thicker than an omega’s, but being the Commander in charge had its perks. 

Such as a nicely decorated room, special food and more protection during missions were just some of the upsides of being Commander for the Survey Corps. 

Armin was blessed, to have such a powerful and strong mate to lie beside him now; and hopefully for the rest of their lives. It didn’t take much for Armin’s mind to instantly become jumbled again, filled with desire that burned through his soul like a star shooting across the sky. 

His alpha suddenly grew impatient, wishing for nothing more than to claim this little omega as his own; whether or not the rest of the factional leaders agreed with Erwin’s decision. 

He was proud in knowing that no matter which fights they might endure, they’d at least have each other. And that takes you a long way. 

The alpha’s cock was bigger than Armin’s, but he took great pleasure in knowing that that knot would soon be buried deep within himself. Erwin took one last glance upwards, towards his mate’s face, waiting for confirmation. 

“ _ Omega… _ we don’t need to do this if you’re not ready. I can wait.” But every tone behind the words told the blond little omega that his alpha desperately didn’t want to wait. And neither did Armin. 

“I want you,  _ Alpha…  _ make me yours. Show the world to whom I belong.” There was no need for foreplay, Armin being wetter than a man without protection in a downpour. Though, Erwin did not wish to harm his mate… 

He eased his swollen member into the smaller male, watching every subtle expression on his delicate features. They changed, almost imperceptibly. It started with a small crease between his eyebrows, followed by the slacking of his jaw and finally - when he was buried to the hilt - Armin’s expression exploded. 

From a small flap of its wings, the butterfly had created a storm. 

His omega was panting with want, unable to keep his desire at bay. The alpha moved his hips slowly, ushering his knot in and out at a steady pace. 

“Armin.” He buried his face in the other’s scent gland, smelling the strong, sweet essence of his heat. His thrusts became harsher, intending not to harm, but to bring pleasure. 

And the blond omega didn’t mind a little bit of a rough treatment; so long as there was an underlying tone of affection. His alpha could be as dominant as he wanted… so long as the omega would get to be the same. 

Armin was seeking out his own release, gripping his cock firmly and pumping the length in the same speed as the thrusts. It was infuriating that he could not come until his alpha had; as he required the other’s knot to swell inside of him. 

“ _ Faster…”  _ He moaned in wanton, not giving a flying fuck that he was submitting completely. Armin was not Levi, no… but he still wouldn’t let just any alpha control him like this. 

_ Just my alpha. _

Erwin complied with his mate’s wishes, snapping his hips in and out; until the slapping sound of skin against skin became almost abusive. He slowed his pace slightly, but the omega’s ankles at the bottom of his spine urged him to not. 

Armin wanted to release just as much as Erwin did. 

So with one final thrust, the alpha felt his knot swell up; shooting seed into his little mate. 

The omega cried out, sinking his teeth into the Commander’s scent gland as a way to mark him. He felt the other’s canines bury themselves in his skin as he finally came. Erwin didn’t want to move, but at the same time didn’t wish to crush his little omega. 

Reluctantly, and carefully, he rolled over; bringing Armin to rest atop him while they both caught their breaths. The omega was smiling contently, taking one big inhale of air; speaking as he exhaled. 

“Have you heard of the chaos theory,  _ alpha? _ ” He purred. 

“A butterfly flaps its wings… and it starts to rain.” The other replied. 

_ The universe made the right choice bringing us together…  _

 

* * *

 

_ Each smallest act of kindness, reverberates across great distances and spans of time --affecting lives unknown to the one who’s generous spirit, was the source of this good echo. Because kindness is passed on and grows each time it’s passed until a simple courtesy becomes an act of selfless courage, years later, and far away. Likewise, each small meanness, each expression of hatred, each act of evil.”  
  
_ ___ \- Dean Koontz, From the Corner of His Eye. _

 

 

**Author's Note:**

> Guys… I did the thing. I wrote the thing! Oh my God! I thought this was going to be a Hell of a lot harder to write, but it just basically wrote itself. Lol XD. 
> 
> Thank you all so much for reading! I love you all! And thank you for all the feedback on “Levi doesn’t do romance… or Eren.” It means so much to me to have you guys read and actually like it! So thank you, from the bottom of my heart! 
> 
> Until next time, JA NE!


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